Commit Graph

22 Commits

Author SHA1 Message Date
caryclark
26ad22ab61 Enabling clip stack flattening exercises path ops.
Iterating through the 903K skps that represent the
imagable 1M top web pages triggers a number of
bugs, some of which are addressed here.

Some web pages trigger intersecting cubic
representations of arc with their conic
counterparts. This exposed a flaw in coincident
detection that caused an infinite loop. The loop
alternatively extended the coincident section and,
determining the that the bounds of the curve pairs
did not overlap, deleted the extension.

Track the number of times the coincident detection
is called, and if it exceeds an empirically found
limit, assume that the curves are coincident and
force it to be so.

The loop count limit can be determined by enabling
DEBUG_T_SECT_LOOP_COUNT and running all tests. The
largest count is reported on completion.

Another class of bugs was caused by concident
detection duplicating nearly identical points that
had been merged earlier. To track these bugs, the
'handle coincidence' code was duplicated as a
const debug variety that reported if one of a
dozen or so irregularities are present; then it is
easier to see when a block of code that fixes one
irregularity regresses another.

Creating the debug const code version exposed some
non-debug code that could be const, and some that
was experimental and could be removed. Set
DEBUG_COINCIDENCE to track coincidence health and
handling.

For running on Chrome, DEBUG_VERIFY checks the
result of pathops against the same operation
using SkRegion to verify that the results are
nearly the same.

When visualizing the pathops work using
tools/pathops_visualizer.htm, set
DEBUG_DUMP_ALIGNMENT to see the curves after
they've been aligned for coincidence.

Other bugs fixed include detecting when a
section of a pair of curves have devolved into
lines and are coincident.

TBR=reed@google.com

Review URL: https://codereview.chromium.org/1394503003
2015-10-16 09:03:38 -07:00
caryclark
27c8eb8ffd When three or more edges are coincident, the logic needs
to compute the overlapping ranges and combine the winding
into a single destination.

This computes coincidence more rigorously, fixing the
edge cases exposed by this bug.

Also, add the ability to debug and dump pathop structures
from the coincident context.

TBR=reed@google.com
BUG=skia:3651

Review URL: https://codereview.chromium.org/1182493015
2015-07-06 11:38:33 -07:00
caryclark
4e1a4c9399 fix builder winding again
Record the nesting level when finding the edge winding contribution
so that inner edges can be reversed as needed.

R=fmalita@chromium.org
BUG=skia:3838

Review URL: https://codereview.chromium.org/1140383002
2015-05-18 12:56:58 -07:00
caryclark
182b499cd7 look for deleted pts when detecting line/curve coincident edges
TBR=reed@google.com
BUG=skia:3651

Review URL: https://codereview.chromium.org/1129863007
2015-05-14 05:45:54 -07:00
caryclark
bca19f7747 deal more consistently with unsortable edges
Improve line/curve coincident detection and resolution. This fixed the remaining simple failures.

When an edge is unsortable, use the ray intersection to determine the angles' winding.

Deal with degenerate segments.

TBR=reed@google.com
BUG=skia:3588,skia:3762

Review URL: https://codereview.chromium.org/1140813002
2015-05-13 08:23:48 -07:00
caryclark
624637cc8e Path ops formerly found the topmost unprocessed edge and determined its angle sort order to initialize the winding. This never worked correctly with cubics and was flaky with paths consisting mostly of vertical edges.
This replacement shoots axis-aligned rays through all intersecting edges to find the outermost one either horizontally or vertically. The resulting code is smaller and twice as fast.

To support this, most of the horizontal / vertical intersection code was rewritten and standardized, and old code supporting the top-directed winding was deleted.

Contours were pointed to by an SkTDArray. Instead, put them in a linked list, and designate the list head with its own class to ensure that methods that take lists of contours start at the top. This change removed a large percentage of memory allocations used by path ops.

TBR=reed@google.com
BUG=skia:3588

Review URL: https://codereview.chromium.org/1111333002
2015-05-11 07:21:28 -07:00
caryclark
aec2510125 minor fixes to cubics code and overall alignment of how bounds and tops are computed for all curve types
All but 17 extended tests work.

A helper function is privately added to SkPath.h to permit a test to modify a given point in a path.

BUG=skia:3588

Review URL: https://codereview.chromium.org/1107353004
2015-04-29 08:28:30 -07:00
caryclark
08bc8488fa fix multiple intersection logic
When three or more curves intersect at the same point, ensure that
each curve records the intersections of the others. This fixes a
number of cubic tests.

TBR=reed@google.com
BUG=skia:3588

Review URL: https://codereview.chromium.org/1105943002
2015-04-24 09:08:57 -07:00
caryclark
03b03cad01 working on initial winding for cubics
Path ops works well for all tests except for cubics.
Isolate failures caused by cubics, and do a better job of computing
the initial winding for cubics.

TBR=reed@google.com
BUG=skia:3588

Review URL: https://codereview.chromium.org/1096923003
2015-04-23 09:13:37 -07:00
caryclark
1049f1246e Now, path ops natively intersect conics, quads, and cubics in any combination. There are still a class of cubic tests that fail and a handful of undiagnosed failures from skps and fuzz tests, but things are much better overall.
Extended tests (150M+) run to completion in release in about 6 minutes; the standard test suite exceeds 100K and finishes in a few seconds on desktops.

TBR=reed
BUG=skia:3588

Review URL: https://codereview.chromium.org/1037953004
2015-04-20 08:31:59 -07:00
caryclark
54359294a7 cumulative pathops patch
Replace the implicit curve intersection with a geometric curve intersection. The implicit intersection proved mathematically unstable and took a long time to zero in on an answer.

Use pointers instead of indices to refer to parts of curves. Indices required awkward renumbering.

Unify t and point values so that small intervals can be eliminated in one pass.

Break cubics up front to eliminate loops and cusps.

Make the Simplify and Op code more regular and eliminate arbitrary differences.

Add a builder that takes an array of paths and operators.

Delete unused code.

BUG=skia:3588
R=reed@google.com

Review URL: https://codereview.chromium.org/1037573004
2015-03-26 07:52:43 -07:00
reed
0dc4dd6dda Revert of pathops version two (patchset #16 id:150001 of https://codereview.chromium.org/1002693002/)
Reason for revert:
ASAN investigation

Original issue's description:
> pathops version two
>
> R=reed@google.com
>
> marked 'no commit' to attempt to get trybots to run
>
> TBR=reed@google.com
>
> Committed: https://skia.googlesource.com/skia/+/ccec0f958ffc71a9986d236bc2eb335cb2111119

TBR=caryclark@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1029993002
2015-03-24 13:55:33 -07:00
caryclark
ccec0f958f pathops version two
R=reed@google.com

marked 'no commit' to attempt to get trybots to run

TBR=reed@google.com

Review URL: https://codereview.chromium.org/1002693002
2015-03-24 07:28:17 -07:00
caryclark
65f553182a These tests stress pathops by describing the union of circle-like paths that have tiny line segments embedded and double back to create near-coincident conditions.
The fixes include
- detect when finding the active top loops between two possible answers
- preflight chasing winding to ensure answer is consistent
- binary search more often when quadratic intersection fails
- add more failure paths when an intersect is missed

While this fixes the chrome bug, reenabling path ops in svg should be deferred until additional fixes are landed.

TBR=
BUG=421132

Committed: https://skia.googlesource.com/skia/+/6f726addf3178b01949bb389ef83cf14a1d7b6b2

Review URL: https://codereview.chromium.org/633393002
2014-11-13 06:58:52 -08:00
hcm
27c46a08a9 Revert of harden pathops for pathological test (patchset #19 id:410001 of https://codereview.chromium.org/633393002/)
Reason for revert:
Compile errors on bots

Original issue's description:
> These tests stress pathops by describing the union of circle-like paths that have tiny line segments embedded and double back to create near-coincident conditions.
>
> The fixes include
> - detect when finding the active top loops between two possible answers
> - preflight chasing winding to ensure answer is consistent
> - binary search more often when quadratic intersection fails
> - add more failure paths when an intersect is missed
>
> While this fixes the chrome bug, reenabling path ops in svg should be deferred until additional fixes are landed.
>
> TBR=
> BUG=421132
>
> Committed: https://skia.googlesource.com/skia/+/6f726addf3178b01949bb389ef83cf14a1d7b6b2

TBR=caryclark@google.com
NOTREECHECKS=true
NOTRY=true
BUG=421132

Review URL: https://codereview.chromium.org/686843002
2014-10-28 10:55:54 -07:00
caryclark
6f726addf3 These tests stress pathops by describing the union of circle-like paths that have tiny line segments embedded and double back to create near-coincident conditions.
The fixes include
- detect when finding the active top loops between two possible answers
- preflight chasing winding to ensure answer is consistent
- binary search more often when quadratic intersection fails
- add more failure paths when an intersect is missed

While this fixes the chrome bug, reenabling path ops in svg should be deferred until additional fixes are landed.

TBR=
BUG=421132

Review URL: https://codereview.chromium.org/633393002
2014-10-28 10:33:09 -07:00
caryclark
630240d188 fail early if coincidence can't be resolved
Bail out if a very large value causes coincidence resolution to
fail.

TBR=
BUG=415866

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/585913002
2014-09-19 06:33:31 -07:00
caryclark
65b427cff9 fix battlefield website by disallowing very small coordinates
also add and remove comments to document other attempts to fix this that had drawbacks

R=fmalita@chromium.org
BUG=414409

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/575553003
2014-09-18 10:32:57 -07:00
caryclark
80a83adaf2 relax quadratic binary search test
Extreme implicit quartic equations solve to roots that are different
enough that they appear to have failed. In this case, fall back on
binary searching to find an intersection.

Relax the condition when this happens; don't give up just because the
computed implicit root points aren't remotely the same.

TBR=reed
BUG=skia:2808

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/456383003
2014-08-12 05:49:37 -07:00
caryclark
19eb3b2f0a update pathops core and tests
split out skpclip (the test of 1M pictures) into its own project

TBR=reed

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/400033002
2014-07-18 05:08:14 -07:00
caryclark
e4097e3a0b Fix last pathops skp bug
This fixes the last bug discovered by iterating through the 800K
skp corpus representing the top 1M websites. For every clip on the
stack, the paths are replaced with the pathop intersection. The
resulting draw is compared with the original draw for pixel errors.

At least two prominent bugs remain. In one, the winding value is
confused by a cubic with an inflection. In the other, a quad/cubic
pair, nearly coincident, fails to find an intersection.

These minor changes include ignoring very tiny self-intersections
of cubics, and processing degenerate edges that don't connect to
anything else.

R=reed@android.com
TBR=reed

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/340103002
2014-06-18 07:24:19 -07:00
caryclark
dac1d17027 Enabling the canvas bit to turn the clip stack into a flat replace exposed around 100 failures when testing the 800K skp set generated from the top 1M web sites.
This fixes all but one of those failures.

Major changes include:
- Replace angle indices with angle pointers. This was motivated by the need to add angles later but not renumber existing angles.
- Aggressive segment chase. When the winding is known on a segment, more aggressively passing that winding to adjacent segments allows fragmented data sets to succeed.
- Line segments with ends nearly the same are treated as coincident first.
- Transfer partial coincidence by observing that if segment A is partially coincident to B and C then B and C may be partially coincident.

TBR=reed

Author: caryclark@google.com

Review URL: https://codereview.chromium.org/272153002
2014-06-17 05:15:38 -07:00